The demand for content is there, yes. But they're not obligated to provide expansions - because people have already bought the main game - and they want as much extra content as is available. What are people going to do? Stop buying extra content? No, they want what they can get. Even if informed gamers like the core segment stopped buying DLC - the casuals are calling the shots.

When people like you are so eager to support DLC as a concept, and you shrug off the lack of expansions - there really is no hope.

If you really believe DLC exists because companies genuinely think that's what people prefer - then I don't know what to say.

Suffice it to say that I don't agree

That's not to say there are no exceptions. Quality DLC exists - and Bethesda and Fallout/TES are good examples. It's just going to be very, very rare. Again, simply because it's easier to produce limited content and offer it for cheap.

It's also why you're seeing a zillion iPad/Smartphone games on the market - but only a tiny, tiny handful of them offering comparable depth to a PC game. Why make a really deep iPad game when you can make something superficial and sell it for 5$ to so many? There's no reason except artistic integrity - and THAT is one scarce commodity.